The invention relates to a torsional vibration damper comprising a hub ring surrounded by a flyring, the two being united by at least one resilient member and being angularly displaceable relative to each other, the resilient member being of columnar shape and extending in the radial direction, and a clearance being provided next to the resilient member in the circumferential direction between the hub ring and the flyring.
A torsional vibration damper of this type is known from German published patent application No. 33 34 393. The damping of torsional vibrations achieved with this device is based on the utilization of absorption effects. At resonance, the device is extraordinarily effective; but its effectiveness is limited to this one case. Vibrations in a different frequency range are not damped, or only poorly damped. This torsional vibration damper is therefore useful only where unwanted vibrations of a single frequency range can occur.
In an attempt to utilize the absorption effect in a self-contained torsional vibration damper for damping resonant vibrations of different frequency regions, it has already been proposed to use a plurality of flywheel masses which are elastically coupled to the hub or to one another. In this case, the individual flywheel systems are coordinated so that each is optimally designed for the damping of unwanted vibrations in a different frequency range. Such a multi-frequency torsional vibration damper is disclosed in the German design Pat. No. 19 97 151.
Thus, depending upon the frequency range of the vibrations introduced, one or the other of the incorporated flywheel systems is alternately activated and alone engaged to damp the disturbing vibrations. However, the presence of the other systems, and particularly of the inertial masses which they comprise, not only detracts from the effectiveness of the damper but also accounts for its considerable weight and high manufacturing cost. There is therefore a need for a resonant vibration damper for rotary motion that does not include such drawbacks.